Detergent tablet containing bleach activator of specific particle size

ABSTRACT

A detergent tablet which contains a bleach activator is disclosed. The bleach activator is in particulate form and has a particle size in a range of from about 100 microns to about 4000 microns. The bleach activator is present in a range of from about 0.1% to about 15% by weight of the detergent tablet.

This application claims the benefit of U.S. Provisional Application No.60/083,256, filed Apr. 27, 1998.

FIELD OF THE INVENTION

The present invention relates generally to a non-particulate detergentproduct, and particularly to a non-particulate detergent productcontaining bleach activator particles dispersed within a high densitycompressed detergent matrix for improved bleach activator activity,stability and performance.

BACKGROUND OF THE INVENTION

Surface bleaching of textiles is a bleaching mechanism that occurs onthe textile surface and, thereby, removes stains and/or soils. Typicalbleaching compositions contain peroxygen bleaches capable of yieldinghydrogen peroxide in aqueous solutions and bleach activators to enhancebleach performance. It has long been known that peroxygen bleaches areeffective for stain and/or soil removal from textiles, but that they arealso extremely temperature dependent. Such bleaches are essentially onlypracticable and/or effective in bleaching solutions, i.e., a bleach andwater mixture, wherein the solution temperature is above about 60° C. Atbleach solution temperatures of about 60° C., peroxygen bleaches areonly partially effective and, therefore, in order to obtain a desirablelevel of bleaching performance extremely high levels of peroxygen bleachmust be added to the system. This is economically impracticable forlarge-scale commercialization of modern detergent products. As thebleach solution temperature is lowered below 60° C., peroxygen bleachesare rendered ineffective, regardless of the level of peroxygen bleachadded to the system. The temperature dependence of peroxygen bleaches issignificant because such bleaches are commonly used as a detergentadjuvant in textile wash processes that utilize an automatic householdwashing machine at wash water temperatures below 60° C. Such washtemperatures are utilized because of textile care and energyconsiderations. As a consequence of such a wash process, there has beenmuch industrial research to develop substances, generally referred to asbleach activators, that render peroxygen bleaches effective at bleachsolution temperatures below 60° C.

Numerous substances have been disclosed in the art as effective bleachactivators. For example, bleach activators having the general formula

wherein R is an alkyl group and L is a leaving group, have beendisclosed in the art. Such bleach activators have typically beenincorporated into detergent products as an admixed granule, agglomerateor other type of particle. However, one problem with such bleachactivators is maintaining the stability of the activator prior to use bythe consumer. The bleach activator granule or agglomerate has a tendencyto degrade over time which is exacerbated by exposure to environmentaleffects such as heat and humidity. As a consequence of this, thegranule, agglomerate or other particulate form of the bleach activatormust be relatively large in comparison to the other detergentingredients in a typical granular detergent product. This, in turn,causes another problem associated with detergent product segregation inthat the larger bleach activator particles tend to accumulate at or nearthe top of the detergent box while relatively smaller particle sizeddetergent ingredients accumulate at or near the bottom of the box.Additionally, particle segregation occurs during the detergentmanufacturing process, leading to increased box to box variability forthe detergent active ingredients. The net result of such an undesirableproduct segregation is decreased performance since the user scoops theproduct from the top to the bottom and each scoop has a disproportionateamount of bleach activator or other detergent ingredient, and similarly,the performance of product from different boxes is affected by variancein the detergent composition.

Thus, it is desirable to have a detergent product containing a bleachactivator which has improved stability prior to use, and which does notsignificantly segregate prior to packaging or while stored in thedetergent product box. Additionally, it is desirable to have a detergentcomposition which also has acceptable physical properties, for example,acceptable flow properties for bulk handling of the composition as partof large-scale detergent manufacturing.

Yet another problem with the aforementioned bleach activators relates tothe inability to advertise the sanitization effects of theabove-mentioned bleach/bleach activator systems on fabrics. Currently,most government regulation agencies require that sanitizationadvertising claims for fabric care can only be made if a relatively highlevel of microbes are consistently removed from the laundered fabrics asa result of using the bleach-containing detergent product. In the past,however, the relatively large granule, agglomerate or other particleform of the bleach activator has inhibited such sanitization advertisingclaims in that the product segregation effects of such larger particlesprevented the consistent removal of high levels of microbes from thelaundered fabrics. The bleach/bleach activator delivery during thelaundering process varied too widely to satisfy most governmental agencyrequirements for sanitization advertising claims. It is thereforedesirable to have a bleach-containing detergent product which can beused to sanitize fabrics.

Accordingly, there remains a need in the art to have a detergent productcontaining a bleach activator which has improved stability prior to use.Also, there is a need in the art for a detergent product containing ableach activator which does not significantly segregate while stored inthe detergent product box and has acceptable physical properties. Yetanother need in the art remains for such a detergent product which has amore consistent bleach/bleach activator delivery.

Non-particulate detergents are an attractive alternative to granular orparticulate forms of detergents from the standpoint of simplifying thedosing of such detergents for automatic laundry or dishwashing machines.Non-particulate detergents are usually supplied in the form of bars,tablets or briquettes and they not only prevent spillage of thedetergent composition but also eliminate the need for the consumer toestimate the correct dosage of the detergent composition per wash.Non-particulate detergents minimize the contact by the consumer with thedetergent.

The present invention exploits some of the advantages of non-particulatedetergents and also solves some of the problems associated withparticulate detergent compositions containing bleach and bleachactivators.

Accordingly, it is an object of the invention to provide anon-particulate detergent product containing bleach activator particleswhich have good stability prior to use and acceptable physicalproperties. It is also an object of the invention to provide anon-particulate detergent product containing bleach activator particleswhich do not segregate while stored in the detergent product box.Another object of the invention is to provide such a detergent productwhich can be used to sanitize fabrics. These and other objects, featuresand attendant advantages of the present invention will become apparentto those skilled in the art from a reading of the following detaileddescription of the preferred embodiment and the appended claims.

BACKGROUND ART

The following references relate to detergent compositions containingbleach activators and/or antimicrobials: U.S. Pat. No. 4,412,934 toChung et al (Procter & Gamble); U.S. Pat. No. 5,021,182 to Jentsch(Roman A. Epp); U.S. Pat. No. 5,489,434 to Oakes et al (Ecolab) and U.S.Pat. No. 4,422,950 to Kemper et al (Lever Brothers Company). Thefollowing references relate to tableted detergents: GB-A-0 989 683,published on Apr. 22nd 1965, discloses a process for preparing aparticulate detergent from surfactants and inorganic salts; spraying onwater-soluble silicate; and pressing the detergent particles into asolid form-retaining tablet. Finally a readily water-soluble organicfilm-forming polymer (for example, polyvinyl alcohol) provides a coatingto make the detergent tablet resistant to abrasion an d accidentalbreakage. European publication a EP-A-0 002 293, published on Jun. 13th1979, discloses a tablet coating comprising hydrated salt such asacetate, metaborate, orthophosphate, tartrate, and sulphate. AnotherEuropean publication, EP-A-0 716 144, published on Jun. 12th 1996, alsodiscloses laundry detergent tablets with water-soluble coatings whichmay be organic polymers including acrylic/maleic co-polymer,polyethylene glycol, PVPVA, and sugar.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a non-particulate detergentproduct containing a bleach activator having the general formula:

is provided. R is an alkyl group containing from about 5 to about 18carbon atoms wherein the longest linear alkyl chain extending from andincluding the carbonyl carbon contains from about 6 to about 10 carbonatoms and L is a leaving group, the conjugate acid of which has a pK_(α)in the range of from about 6 to about 13. The bleach activator is inparticulate form and has a mean particle size in a range of from about100 microns to about 4000 microns. The bleach activator is present in arange of from about 0.1% to about 15% by weight of the non-particulatedetergent product. The bleach activator is dispersed within a matrixformed of the non-particulate detergent product and the bleachactivator, and the matrix has a density of at least 1000 g/l.

The small sized bleach activator particles, which can have variousforms, such as extrudates or irregularly shaped particles, remaindispersed in the compressed matrix and thus do not undergo productsegregation as is often encountered in the case of detergentcompositions in particulate form in a detergent box in which they arecontained. Further, the bleach activator particles exhibit greateractivity because of their smaller size and their consequently largersurface area which more closely mirrors the particle size of otherconventional detergent ingredients. Additionally, the bleach activatorparticles having the above small particle size have acceptable flowproperties and allow the detergent composition to deliver sanitizationeffects to the laundered fabrics more consistently.

In another aspect of the present invention, a method of launderingsoiled clothes includes the step of immersing said soiled clothes in anaqueous medium containing an effective amount of a non-particulatedetergent product made by a process as set forth above.

In still another aspect of the present invention, a method of launderingfabric materials in a washing machine is provided. The method includesthe steps of providing a flexible porous bag adapted for receiving anon-particulate detergent product, providing a non-particulate detergentproduct made according to the process described above, placing thenon-particulate detergent product within the flexible porous bag, andplacing the flexible porous bag containing the detergent product in thewashing machine with the fabric materials to be washed. The flexibleporous bag is adapted for permitting entry of an aqueous washing mediumthrough the bag, thereby dissolving the non-particulate detergentproduct placed therein, into the aqueous washing medium, and releasing aresultant wash solution from inside of the bag to outside of the bag andinto the aqueous wash medium during a wash cycle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the preferred embodiment, the bleach activator particles are in theform of cylindrically shaped extrudates that are chopped into smallparticles.

The phrase “cylindrically-shaped extrudates” means an extruded particlehaving a surface shape generated by a straight line moving parallel to afixed straight line and intersecting a fixed planar closed curve. An“effective amount” of a detergent composition containing a bleachactivator is any amount capable of measurably improving both soilremoval from and sanitization of the fabric when it is washed by theconsumer. In general, this amount may vary quite widely. As used herein,the terms “disinfecting”, “disinfection”, “antibacterial”, “germ kill”,and “sanitization” are intended to mean killing microbes commonly foundin and on fabrics requiring laundering. Examples of various microbesinclude germs, bacteria, viruses, parasites, and fungi/spores. As usedherein, “free water” level means the level on a percentage by weightbasis of water in the detergent composition which is not bound up or inanother detergent ingredient such as zeolite; it is the water level inexcess of any water entrained in, adsorbed in, or otherwise bound up inother detergent ingredients.

In the preferred embodiment of one aspect of the invention, anon-particulate detergent product containing a bleach activator havingthe general formula:

is provided. R is an alkyl group containing from about 5 to about 18carbon atoms wherein the longest linear alkyl chain extending from andincluding the carbonyl carbon contains from about 6 to about 10 carbonatoms and L is a leaving group, the conjugate acid of which has a pK_(α)in the range of from about 6 to about 13. The bleach activator is inparticulate form and has a mean particle size in a range of from about100 microns to about 4000 microns. The bleach activator is present in arange of from about 0.1% to about 15% by weight of the non-particulatedetergent product. The bleach activator is dispersed within a matrixformed of the non-particulate detergent product and the bleachactivator, and the matrix has a density of at least 1000 g/l.

The detergent product of the invention essentially comprises twocomponents, namely, a peroxygen bleaching compound and a bleachactivator in substantially cylindrically-shape extrudate form.Preferably, the peroxygen bleaching compound is capable of yieldinghydrogen peroxide in an aqueous solution. The detergent product of theinvention is unexpectedly stable with respect to the bleach activator interms of maintaining or not degrading over extended storage periodsprior to use. Preferably, one or more binder materials are included inthe bleach activator extrudates including, but not limited to, palmiticacid, a detersive surfactant, polyethylene glycol and other fatty acidsand polyacrylates.

While not intending to be bound by theory, it is believed that byselecting a particle size as described herein, the bleach activatorexhibits increased activity due to large surface area and because thebleach activator particles are affixed in a compressed matrix, there isabsolutely no chance of segregation, resulting in a very consistentrelease of the bleach activator in the wash solution.

In the preferred embodiment, the bleach activator is in particulate formand has a mean particle size preferably in a range of from about 200microns to about 3000 microns, m or e preferably in a range of fromabout 200 microns to about 2000 microns, even more preferably, in arange of from about 200 microns to about 1500 microns, and mostpreferably, in a range of from about 300 microns to about 1000 microns.

To yield acceptable flow properties for bulk handling of the extrudatesbeing mixed in the particulate detergent composition, prior tocompacting, a finely divided inorganic powder may be added as a flow aidto the surface of the extrudates. This flow aid includes, but is notlimited to, finely divided aluminosilicates, silicas, crystallinelayered silicates, MAP zeolites, citrates, amorphous silicates, sodiumcarbonate, and mixtures thereof. It is preferable for the level of theflow aid to be from about 0.1% to about 10%, more preferably from about1% to about 7%, and most preferably from about 1.5% to about 5% byweight of the detergent composition. The most preferable flow aid isaluminosilicate.

The peroxygen bleaching compound is preferably selected from the groupconsisting of sodium perborate monohydrate, sodium perboratetetrahydrate, sodium carbonate peroxyhydrate, sodium pyrophosphateperoxyhydrate, urea peroxyhydrate, sodium peroxide and mixtures thereofIt is preferable for the detergent composition of the invention tocontain less than about 3%, more preferably less than about 2.5%, andmost preferably less than about 2% by weight of free water. While notwishing to be bound by theory, it is believed that by maintaining thisrelatively low level of free water in the composition, the propensity ofthe bleach activator to degrade via hydrolysis prior to use is lowered.Thus, the stability of the bleach activator is enhanced and prolongedeven further as a result of a selected free water level as set forthherein.

The selected relatively smaller particle size and cylindrical shape ofthe bleach activator extrudates affixed within a matrix having a densityof at least 1000 g/l results in a more consistent delivery of activatorto the aqueous laundering solution. Stated differently, the variationaround the target level of bleach activator to be delivered to the washsolution is unexpectedly reduced as result of using a narrow particlesize range of the bleach activators and fixing them in a compresseddetergent matrix.

Fortuitously, this allows the detergent composition to deliver thebleach activator at a more consistent level to achieve sanitizationeffects on the laundered fabrics. Most governmental agencies requirevery little variation around bleach activator or other sanitizing agenttarget levels in order for sanitization advertising claims to be legallymade to the public. Thus, the invention also provides a suitable andconvenient method of sanitizing fabrics which may be suitable for publicadvertising. Preferably, the number of microbes present on said fabricsis reduced by at least about 50%, more preferably reduced by at leastabout 90%, and most preferably reduced by at least about 99.9%. Thissanitizing method is interchangeably used with disinfecting,antibacterial, germ killing, odor-causing germ killing methods inaccordance with the invention.

Additionally, the specific bleach activator and peroxygen bleachingcomposition in the detergent composition are preferably present atspecific molar ratios of hydrogen peroxide to bleach activator. Suchcompositions provide extremely effective and efficient surface bleachingof textiles which thereby remove stains and/or soils from the textiles.Such compositions are particularly effective at removing dingy soilsfrom textiles. Dingy soils are soils that build up on textiles afternumerous cycles of usage and washing and, thus, result in a whitetextile having a gray tint. These soils tend to be a blend ofparticulate and greasy materials. The removal of this type of soil issometimes referred to as “dingy fabric clean up”. The bleach-containingdetergent compositions of this invention provide such bleaching over awide range of bleach solution temperatures. Such bleaching is obtainedin bleach solutions wherein the solution temperature is at least about5° C. Without the bleach activator, such peroxygen bleaches would beineffective and/or impracticable at temperatures below about 60° C.

Much lower levels of the bleach activators within the invention arerequired, on a molar basis, to achieve the same level of surfacebleaching performance that is obtained with similar bleach activatorscontaining only from about 2 to about 5 carbon atoms in the longestlinear alkyl chain extending from and including the carbonyl carbon.Without being bound by theory, it is believed that such efficiency isachieved because the bleach activators within the invention exhibitsurface activity. This can be explained as follows. The bleachingmechanism generally, and the surface bleaching mechanism in particular,are not completely understood. However, it is generally believed thatthe bleach activator undergoes nucleophile attack by a perhydroxideanion, which is generated from the hydrogen peroxide evolved by theperoxygen bleach, to form a percarboxylic acid. This reaction iscommonly referred to as perhydrolysis. The percarboxylic acid then formsa reactive dimer with its anion which, in turn, evolves a singlet oxygenwhich is believed to be the active bleaching component. It is theorizedthat the singlet oxygen must be evolved at or near the textile surfacein order to provide surface bleaching. Otherwise, the singlet oxygenwill provide bleaching, but not at the textile surface. Such bleachingis known as solution bleaching, i.e., the bleaching of soils in thebleach solution.

To ensure that the singlet oxygen is more efficiently evolved at thetextile surface, it is essential that the longest linear alkyl chainextending from and including the carbonyl carbon of the percarboxylicacid have from about 6 to about 10 carbon atoms. Such percarboxylicacids are surface active and, therefore, tend to be concentrated at thetextile surface. Percarboxylic acids containing fewer carbon atoms insuch alkyl chain have similar redox potentials, but do not have theability to concentrate at the textile surface. Therefore, the bleachactivators within the invention are extremely efficient because muchlower levels, on a molar basis, of such bleach activators are requiredto get the same level of surface bleaching performance as with similarbleach activators containing fewer carbon atoms in such an alkyl chain,which are not within the invention.

Optimum surface bleaching performance is obtained with bleachingsolutions wherein the pH of such solution is between about 8.5 and 10.5and preferably between 9 and 10. It is preferred that such pH be greaterthan 9 not only to optimize surface bleaching performance, but also toprevent the bleaching solution from having an undesirable odor. It hasbeen observed that once the pH of the bleaching solution drops below 9,the bleaching solution has an undesirable odor. Such pH can be obtainedwith substances commonly known as buffering agents, which are optionalcomponents of the bleaching compositions herein.

In a highly preferred embodiment of the invention, the substantiallycylindrically-shaped extrudate comprises, by weight of the extrudate,from about 60% to about 95% of a bleach activator, from about 0.1% toabout 10% of palmitic acid, from about 0.1% to about 10% of a detersivesurfactant, from about 0.1% to about 10% of polyethylene glycol, andfrom about 0.1% to about 10% of fatty acid.

Bleach Activators

The bleach activator for the bleaching systems useful herein preferablyhas the following structure:

wherein R is an alkyl group containing from about 5 to about 18 carbonatoms wherein the longest linear alkyl chain extending from andincluding the carbonyl carbon contains from about 6 to about 10 carbonatoms and L is a leaving group, the conjugate acid of which has a pKα inthe range of from about 4 to about 13, preferably from about 6 to about11, most preferably from about 8 to about 11.

L can be essentially any suitable leaving group. A leaving group is anygroup that is displaced from the bleach activator as a consequence ofthe nucleophilic attack on the bleach activator by the perhydroxideanion. This, the perhydrolysis reaction, results in the formation of thepercarboxylic acid. Generally, for a group to be a suitable leavinggroup it must exert an electron attracting effect. This facilitates thenucleophilic attach by the perhydroxide anion.

The L group must be sufficiently reactive for the reaction to occurwithin the optimum time frame (e.g., a wash cycle). However, if L is tooreactive, this activator will be difficult to stabilize. Thesecharacteristics are generally paralleled by the pKα of the conjugateacid of the leaving group, although exceptions to this convention areknown.

Preferred bleach activators are those of the general formula:

wherein R¹ is an alkyl group containing from about 6 to about 12 carbonatoms, R² is an alkylene containing from 1 to about 6 carbon atoms, R⁵is H or alkyl, aryl, or alkaryl containing from about 1 to about 10carbon atoms, and L is selected from the group consisting of:

wherein R⁶ is an alkylene, arylene, or alkarylene group containing fromabout 1 to about 14 carbon atoms, R³ is an alkyl chain containing fromabout 1 to about 8 carbon atoms, R⁴ is H or R³, and Y is H or asolubilizing group. Y is preferably selected from the group consistingof —SO₃—M+, —COO—M+, —SO₄—M+, (—N+R′₃)X— and O←N(R′₃), wherein R′ is analkyl chain containing from about 1 to about 4 carbon atoms, M is acation which provides solubility to the bleach activator and X is ananion which provides solubility to the bleach activator. Preferably, Mis an alkali metal, ammonium or substituted ammonium cation, with sodiumand potassium being most preferred, and X is an anion selected from thegroup consisting of halide, hydroxide, methylsulfate and acetate anions.More preferably, Y is —SO₃—M+ and —COO—M+. It should be noted thatbleach activators with a leaving group that does not contain asolubilizing group should be well dispersed in the bleach solution inorder to assist in their dissolution. Preferred is:

wherein R³ is as defined above and Y is —SO₃—M+ or —COO—M+ wherein M isas defined above.

Especially preferred bleach activators are those wherein R¹ is a linearalkyl chain containing from about 6 to about 12 carbon atoms, R² is alinear alkylene chain containing from about 2 to about 6 carbon atoms,R⁵ is H, and L is selected from the group consisting of:

wherein R³ is as defined above, Y is —SO₃—M+ or —COO—M+ and M is asdefined above.

A preferred bleach activator is:

wherein R is H, alkyl, aryl or alkaryl. This is described in U.S. Pat.No. 4,966,723, Hodge et al., incorporated by reference herein.

Preferred bleach activators are:

wherein R¹ is H or an alkyl group containing from about 1 to about 6carbon atoms and R² is an alkyl group containing from about 1 to about 6carbon atoms and L is as defined above.

Preferred bleach activators are also those of the above general formulawherein L is as defined in the general formula, and R¹ is H or an alkylgroup containing from about 1 to about 4 carbon atoms. Even morepreferred are bleach activators of the above general formula wherein Lis as defined in the general formula and R¹ is a H.

More preferred bleach activators are those of the above general formulawherein R is a linear alkyl chain containing from about 5 to about 12and preferably from about 6 to about 8 carbon atoms and L is selectedfrom the group consisting of:

wherein R, R², R³ and Y are as defined above.

Particularly preferred bleach activators are those of the above generalformula wherein R is an alkyl group containing from about 5 to about 12carbon atoms wherein the longest linear portion of the alkyl chainextending from and including the carbonyl carbon is from about 6 toabout 10 carbon atoms, and L is selected from the group consisting of:

herein R² is an alkyl chain containing from about 1 to about 8 carbonatoms, and Y is —SO₃M+ or —COO—M+ wherein M is an alkali metal, ammoniumor substituted ammonium cation.

Especially preferred bleach activators are those of the above generalformula wherein R is a linear alkyl chain containing from about 5 toabout 12 and preferably from about 6 to about 8 carbon atoms and L isselected from the group consisting of:

wherein R² is as defined above and Y is —SO₃M+ or —COO—M+ wherein M isas defined above.

The most preferred bleach activators have the formula:

wherein R is a linear alkyl chain containing from about 5 to about 12and preferably from about 6 to about 8 carbon atoms and M is sodium orpotassium.

Preferably, the bleach activator herein is sodiumnonanoyloxybenzenesulfonate (NOBS) or sodium benzoyloxybenzenesulfonate(BOBS).

Further particularly preferred for use in the present inventionbleaching compositions are the following bleach activators which areparticularly safe for use with machines having natural rubber parts.This is believed to be the result of not producing oily diacylperoxide(DAP) species by the perhydrolysis reaction of these amido acid-derivedbleach activators, but rather forming insoluble crystalline solid DAP's.These solids are believed to not form a coating film and thus naturalrubber parts are not exposed to DAP's for extended periods of time.These preferred bleach activators are members selected from the groupconsisting of:

a) a bleach activator of the general formula:

or mixtures thereof, wherein R¹ is an alkyl, aryl, or alkaryl groupcontaining from about 1 to about 14 carbon atoms, R² is an alkylene,arylene or alkarylene group containing from about 1 to about 14 carbonatoms, R⁵ is H or an alkyl, aryl, or alkaryl group containing from about1 to about 10 carbon atoms, and L is a leaving group;

b) benzoxazin-type bleach activators of the general formula:

 wherein R₁ is H, alkyl, alkaryl, aryl, arylalkyl, and wherein R₂, R₃,R₄, and R₅ may be the same or different substituents selected from H,halogen, alkyl, alkenyl, aryl, hydroxyl, alkoxyl, amino, alkylamino,COOR₆ (wherein R₆ is H or an alkyl group) and carbonyl functions;

c) N-acyl caprolactam bleach activators of the formula:

 wherein R⁶ is H or an alkyl, aryl, alkoxyaryl or alkaryl groupcontaining from 1 to 12 carbons; and

d) mixtures of a), b) and c).

Preferred bleach activators of type a) are those wherein R¹ is an alkylgroup containing from about 6 to about 12 carbon atoms, R² contains fromabout 1 to about 8 carbon atoms, and R⁵ is H or methyl. Particularlypreferred bleach activators are those of the above general formulaswherein R¹ is an alkyl group containing from about 7 to about 10 carbonatoms and R² contains from about 4 to about 5 carbon atoms.

Preferred bleach activators of type b) are those wherein R₂, R₃, R₄, andR₅ are H and R₁ is a phenyl group.

The preferred acyl moieties of said N-acyl caprolactam bleach activatorsof type c) have the formula R⁶—CO— wherein R⁶ is H or an alkyl, aryl,alkoxyaryl, or alkaryl group containing from 1 to 12 carbons, preferablyfrom 6 to 12 carbon atoms. In highly preferred embodiments, R⁶ is amember selected from the group consisting of phenyl, heptyl, octyl,nonyl, 2,4,4-trimethylpentyl, decenyl and mixtures thereof.

Amido Derived Bleach Activators—The bleach activators of type a)employed in the present invention are amide substituted compounds of thegeneral formulas:

or mixtures thereof, wherein R¹, R² and R⁵ are as defined above and Lcan be essentially any suitable leaving group. Preferred bleachactivators are those of the above general formula wherein R¹, R² and R⁵are as defined for the peroxyacid and L is selected from the groupconsisting of:

and mixtures thereof, wherein R¹ is an alkyl, aryl, or alkaryl groupcontaining from about 1 to about 14 carbon atoms, R³ is an alkyl chaincontaining from 1 to about 8 carbon atoms, R⁴ is H or R³, and Y is H ora solubilizing group.

The preferred solubilizing groups are —SO₃ ⁻M⁺, —CO₂ ⁻M⁺,—SO₄ ^(−M) ⁺,—N⁺(R³)₄X⁻ and O<N(R³)₃ and most preferably —SO₃ ⁻M⁺ and —CO₂ ⁻M⁺wherein R³ is an alkyl chain containing from about 1 to about 4 carbonatoms, M is hydrogen or a cation which provides solubility to the bleachactivator and X is an anion which provides solubility to the bleachactivator. Preferably, M is an alkali metal, hydrogen, ammonium orsubstituted ammonium cation, with sodium and potassium being mostpreferred, and X is a halide, hydroxide, methylsulfate or acetate anion.It should be noted that bleach activators with a leaving group that doesnot contain a solubilizing groups should be well dispersed in thebleaching solution in order to assist in their dissolution.

Preferred bleach activators are those of the above general formulawherein L is selected from the group consisting of:

wherein R³ is as defined above and Y is —SO₃ ⁻M⁺ or —CO₂ ⁺M⁺ wherein Mis as defined above.

Another important class of bleach activators, including those of type b)and type c), provide organic peracids as described herein byring-opening as a consequence of the nucleophilic attack on the carbonylcarbon of the cyclic ring by the perhydroxide anion. For instance, thisring-opening reaction in type c) activators involves attack at thecaprolactam ring carbonyl by hydrogen peroxide or its anion. Sinceattack of an acyl caprolactam by hydrogen peroxide or its anion occurspreferably at the exocyclic carbonyl, obtaining a significant fractionof ring-opening may require a catalyst. Another example of ring-openingbleach activators can be found in type b) activators, such as thosedisclosed in U.S. Pat. No. 4,966,723, Hodge et al, issued Oct. 30, 1990.

Benzoxazin-type Bleach Activators—Such activator compounds disclosed byHodge include the activators of the benzoxazin-type, having the formula:

including the substituted benzoxazins of the type

wherein R₁ is H, alkyl, alkaryl, aryl, arylalkyl, and wherein R₂, R₃,R₄, and R₅ may be the same or different substituents selected from H,halogen, alkyl, alkenyl, aryl, hydroxyl, alkoxyl, amino, alkyl amino,COOR₆ (wherein R₆ is H or an alkyl group) and carbonyl functions.

A preferred activator of the benzoxazin-type is:

When the activators are used, optimum surface bleaching performance isobtained with washing solutions wherein the pH of such solution isbetween about 8.5 and 10.5 and preferably between 9.5 and 10.5 in orderto facilitate the perhydrolysis reaction. Such pH can be obtained withsubstances commonly known as buffering agents, which are optionalcomponents of the bleaching systems herein.

N-Acyl Caorolactam Bleach Activators—The N-acyl caprolactam bleachactivators of type c) employed in the present invention have theformula:

wherein R⁶ is H or an alkyl, aryl, alkoxyaryl, or alkaryl groupcontaining from 1 to 12 carbons. Caprolactam activators wherein the R⁶moiety contains at least about 6, preferably from 6 to about 12, carbonatoms provide hydrophobic bleaching which affords nucleophilic and bodysoil clean-up, as noted above. Caprolactam activators wherein R⁶comprises from 1 to about 6 carbon atoms provide hydrophilic bleachingspecies which are particularly efficient for bleaching beverage stains.Mixtures of hydrophobic and hydrophilic caprolactams, typically atweight ratios of 1:5 to 5:1, preferably 1:1, can be used herein formixed stain removal benefits.

Highly preferred N-acyl caprolactams are selected from the groupconsisting of benzoyl caprolactam, octanoyl caprolactam, nonanoylcaprolactam, 3,5,5-trimethylhexanoyl caprolactam, decanoyl caprolactam,undecenoyl caprolactam, and mixtures thereof. Methods for making N-acylcaprolactams are well known in the art.

Contrary to the teachings of U.S. Pat. No. 4,545,784, the bleachactivator is preferably not absorbed onto the peroxygen bleachingcompound. To do so in the presence of other organic detersiveingredients could cause safety problems.

The bleach activators of type a), b) or c) will comprise at least about0.1%, preferably from about 0.1% to about 50%, more preferably fromabout 1% to about 30%, most preferably from about 3% to about 25%, byweight of bleaching system or detergent composition.

The preferred amido-derived and caprolactam bleach activators herein canalso be used in combination with rubber-safe, enzyme-safe, hydrophilicactivators such as TAED, typically at weight ratios of amido-derived orcaprolactam activators:TAED in the range of 1:5 to 5:1, preferably about1:1.

The Peroxygen Bleaching Compound

The peroxygen bleaching systems useful herein are those capable ofyielding hydrogen peroxide in an aqueous liquor. These compounds arewell known in the art and include hydrogen peroxide and the alkali metalperoxides, organic peroxide bleaching compounds such as urea peroxide,and inorganic persalt bleaching compounds, such as the alkali metalperborates, percarbonates, perphosphates, and the like. Mixtures of twoor more such bleaching compounds can also be used, if desired.

Preferred peroxygen bleaching compounds include sodium perborate,commercially available in the form of mono-, tri-, and tetra-hydrate,sodium pyrophosphate peroxybydrate, urea peroxyhydrate, sodiumpercarbonate, and sodium peroxide. Particularly preferred are sodiumperborate tetrahydrate, sodium perborate monohydrate and sodiumpercarbonate. Percarbonate is especially preferred because it is verystable during storage and yet still dissolves very quickly in thebleaching liquor. It is believed that such rapid dissolution results inthe formation of higher levels of percarboxylic acid and, thus, enhancedsurface bleaching performance.

Highly preferred percarbonate can be in uncoated or coated form. Theaverage particle size of uncoated percarbonate ranges from about 400 toabout 1200 microns, most preferably from about 400 to about 600 microns.If coated percarbonate is used, the preferred coating materials includemixtures of carbonate and sulphate, silicate, borosilicate, or fattycarboxylic acids.

The peroxygen bleaching compound will comprise at least about 0.1%,preferably from about 1% to about 75%, more preferably from about 3% toabout 40%, most preferably from about 3% to about 25%, by weight ofbleaching system or detergent composition. The weight ratio of bleachactivator to peroxygen bleaching compound in the bleaching systemtypically ranges from about 2:1 to 1:5. Preferred ratios range fromabout 1:1 to about 1:3. The molar ratio of hydrogen peroxide yielded bythe peroxygen bleaching compound to the bleach activator is greater thanabout 1.0, more preferably greater than about 1.5, and most preferablyfrom about 2.0 to about 10. Preferably, the bleaching compositionsherein comprise from about 0.5 to about 20, most preferably from about 1to about 10, wt. % of the peroxygen bleaching compound.

The bleach activator/bleaching compound systems herein are useful per seas bleaches. However, such bleaching systems are especially useful incompositions which can comprise various detersive adjuncts such assurfactants, builders and the like.

Adjunct Detergent Ingredients

Preferably, adjunct detergent ingredients selected from the groupconsisting of enzymes, soil release agents, dispersing agents, opticalbrighteners, suds suppressors, fabric softeners, enzyme stabilizers,perfumes, dyes, fillers, dye transfer inhibitors and mixtures thereofare included in the composition of the invention. The following arerepresentative examples of the detergent surfactants useful in thepresent detergent composition. Water-soluble salts of the higher fattyacids, i.e., “soaps”, are useful anionic surfactants in the compositionsherein. This includes alkali metal soaps such as the sodium, potassium,ammonium, and alkylolammonium salts of higher fatty acids containingfrom about 8 to about 24 carbon atoms, and preferably from about 12 toabout 18 carbon atoms. Soaps can be made by direct saponification offats and oils or by the neutralization of free fatty acids. Particularlyuseful are the sodium and potassium salts of the mixtures of fatty acidsderived from coconut oil and tallow, i.e., sodium or potassium tallowand coconut soap.

Additional anionic surfactants which suitable for use herein include thewater-soluble salts, preferably the alkali metal, ammonium andalkylolammonium salts, of organic sulfuric reaction products having intheir molecular structure a straight-chain alkyl group containing fromabout 10 to about 20 carbon atoms and a sulfonic acid or sulfuric acidester group. (Included in the term “alkyl” is the alkyl portion of acylgroups.) Examples of this group of synthetic surfactants are the sodiumand potassium alkyl sulfates, especially those obtained by sulfating thehigher alcohols (C₈₋₁₈ carbon atoms) such as those produced by reducingthe glycerides of tallow or coconut oil; and the sodium and potassiumalkylbenzene sulfonates in which the alkyl group contains from about 9to about 15 carbon atoms, in straight chain, e.g., those of the typedescribed in U.S. Pat. Nos. 2,220,099 and 2,477,383. Especially valuableare linear straight chain alkylbenzene sulfonates in which the averagenumber of carbon atoms in the alkyl group is from about 11 to 13,abbreviated as C₁₁₋₁₃ LAS.

Other anionic surfactants suitable for use herein are the sodium alkylglyceryl ether sulfonates, especially those ethers of higher alcoholsderived from tallow and coconut oil; sodium coconut oil fatty acidmonoglyceride sulfonates and sulfates; sodium or potassium of ethyleneoxide per molecule and wherein the alkyl groups contain from about 8 toabout 12 carbon atoms; and sodium or potassium salts of alkyl ethyleneoxide ether sulfates containing about 1 to about 10 units of ethyleneoxide per molecule and wherein the alkyl group contains from about 10 toabout 20 carbon atoms.

In addition, suitable anionic surfactants include the water-solublesalts of esters of alpha-sulfonated fatty acids containing from about 6to 20 carbon atoms in the fatty acid group and from about 1 to 10 carbonatoms in the ester group; water-soluble salts of2-acyloxyalkane-1-sulfonic acids containing from about 2 to 9 carbonatoms in the acyl group and from about 9 to about 23 carbon atoms in thealkane moiety; alkyl ether sulfates containing from about 10 to 20carbon atoms in the alkyl group and from about 1 to 30 moles of ethyleneoxide; water-soluble salts of olefin and paraffin sulfonates containingfrom about 12 to 20 carbon atoms; and beta-alkyloxy alkane sulfonatescontaining from about 1 to 3 carbon atoms in the alkyl group and fromabout 8 to 20 carbon atoms in the alkane moiety.

Preferred essential anionic surfactants for the detergent compositionare C₁₀₋₁₈ linear alkylbenzene sulfonate and C₁₀₋₁₈ alkyl sulfate. Ifdesired, low moisture (less than about 25% water) alkyl sulfate pastecan be the sole ingredient in the surfactant paste. Most preferred areC₁₀₋₁₈ alkyl sulfates, linear or branched, and any of primary, secondaryor tertiary. A preferred embodiment of the present invention is whereinthe surfactant paste comprises from about 20% to about 40% of a mixtureof sodium C₁₀₋₁₃ linear alkylbenzene sulfonate and sodium C₁₂₋₁₆ alkylsulfate in a weight ratio of about 2:1 to 1:2.

Water-soluble nonionic surfactants are also useful in the instantinvention. Such nonionic materials include compounds produced by thecondensation of alkylene oxide groups (hydrophilic in nature) with anorganic hydrophobic compound, which may be aliphatic or alkyl aromaticin nature. The length of the polyoxyalkylene group which is condensedwith any particular hydrophobic group can be readily adjusted to yield awater-soluble compound having the desired degree of balance betweenhydrophilic and hydrophobic elements.

Suitable nonionic surfactants include the polyethylene oxide condensatesof alkyl phenols, e.g., the condensation products of alkyl phenolshaving an alkyl group containing from about 6 to 15 carbon atoms, ineither a straight chain or branched chain configuration, with from about3 to 12 moles of ethylene oxide per mole of alkyl phenol. Included arethe water-soluble and water-dispersible condensation products ofaliphatic alcohols containing from 8 to 22 carbon atoms, in eitherstraight chain or branched configuration, with from 3 to 12 moles ofethylene oxide per mole of alcohol.

An additional group of nonionics suitable for use herein are semi-polarnonionic surfactants which include water-soluble amine oxides containingone alkyl moiety of from abut 10 to 18 carbon atoms and two moietiesselected from the group of alkyl and hydroxyalkyl moieties of from about1 to about 3 carbon atoms; water-soluble phosphine oxides containing onealkyl moiety of about 10 to 18 carbon atoms and two moieties selectedfrom the group consisting of alkyl groups and hydroxyalkyl groupscontaining from about 1 to 3 carbon atoms; and water-soluble sulfoxidescontaining one alkyl moiety of from about 10 to 18 carbon atoms and amoiety selected from the group consisting of alkyl and hydroxyalkylmoieties of from about 1 to 3 carbon atoms.

Preferred nonionic surfactants are of the formula R¹(OC₂H₄)_(n)OH,wherein R¹ is a C₁₀-C₁₆ alkyl group or a C₈-C₁₂ alkyl phenyl group, andn is from 3 to about 80. Particularly preferred are condensationproducts of C₁₂-C₁₅ alcohols with from about 5 to about 20 moles ofethylene oxide per mole of alcohol, e.g., C₁₂-C₁₃ alcohol condensed withabout 6.5 moles of ethylene oxide per mole of alcohol.

Additional suitable nonionic surfactants include polyhydroxy fatty acidamides. Examples are N-methyl N-1-deoxyglucityl cocoamide and N-methylN-1-deoxyglucityl oleamide. Processes for making polyhydroxy fatty acidamides are known and can be found in Wilson, U.S. Pat. No. 2,965,576 andSchwartz, U.S. Pat. No. 2,703,798, the disclosures of which areincorporated herein by reference.

Ampholytic surfactants include derivatives of aliphatic or aliphaticderivatives of heterocyclic secondary and tertiary amines in which thealiphatic moiety can be straight chain or branched and wherein one ofthe aliphatic substituents contains from about 8 to 18 carbon atoms andat least one aliphatic substituent contains an anionicwater-solubilizing group.

Zwitterionic surfactants include derivatives of aliphatic, quaternary,ammonium, phosphonium, and sulfonium compounds in which one of thealiphatic substituents contains from about 8 to 18 carbon atoms.

Cationic surfactants can also be included in the present invention.Cationic surfactants comprise a wide variety of compounds characterizedby one or more organic hydrophobic groups in the cation and generally bya quaternary nitrogen associated with an acid radical. Pentavalentnitrogen ring compounds are also considered quaternary nitrogencompounds. Suitable anions are halides, methyl sulfate and hydroxide.Tertiary amines can have characteristics similar to cationic surfactantsat washing solution pH values less than about 8.5. A more completedisclosure of these and other cationic surfactants useful herein can befound in U.S. Pat. No. 4,228,044, Cambre, issued Oct. 14, 1980,incorporated herein by reference.

Cationic surfactants are often used in detergent compositions to providefabric softening and/or antistatic benefits. Antistatic agents whichprovide some softening benefit and which are preferred herein are thequaternary ammonium salts described in U.S. Pat. No. 3,936,537,Baskerville, Jr. et al., issued Feb. 3, 1976, the disclosure of which isincorporated herein by reference.

In addition to a detersive surfactant, at least one suitable adjunctdetergent ingredient such as a builder is preferably included in thedetergent composition. For example, the builder can be selected from thegroup consisting of aluminosilicates, crystalline layered silicates, MAPzeolites, citrates, amorphous silicates, polycarboxylates, sodiumcarbonates and mixtures thereof. Other suitable auxiliary builders aredescribed hereinafter.

Preferred builders include aluminosilicate ion exchange materials andsodium carbonate. The aluminosilicate ion exchange materials used hereinas a detergent builder preferably have both a high calcium ion exchangecapacity and a high exchange rate. Without intending to be limited bytheory, it is believed that such high calcium ion exchange rate andcapacity are a function of several interrelated factors which derivefrom the method by which the aluminosilicate ion exchange material isproduced. In that regard, the aluminosilicate ion exchange materialsused herein are preferably produced in accordance with Corkill et al,U.S. Pat. No. 4,605,509 (Procter & Gamble), the disclosure of which isincorporated herein by reference.

Preferably, the aluminosilicate ion exchange material is in “sodium”form since the potassium and hydrogen forms of the instantaluminosilicate do not exhibit the as high of an exchange rate andcapacity as provided by the sodium form. Additionally, thealuminosilicate ion exchange material preferably is in over dried formso as to facilitate production of crisp detergent agglomerates asdescribed herein. The aluminosilicate ion exchange materials used hereinpreferably have particle size diameters which optimize theireffectiveness as detergent builders. The term “particle size diameter”as used herein represents the average particle size diameter of a givenaluminosilicate ion exchange material as determined by conventionalanalytical techniques, such as microscopic determination and scanningelectron microscope (SEM). The preferred particle size diameter of thealuminosilicate is from about 0.1 micron to about 10 microns, morepreferably from about 0.5 microns to about 9 microns. Most preferably,the particle size diameter is from about 1 microns to about 8 microns.

Preferably, the aluminosilicate ion exchange material has the formula

Naz[(AIO₂)_(z).(SiO₂)_(y)]xH₂O

wherein z and y are integers of at least 6, the molar ratio of z to y isfrom about 1 to about 5 and x is from about 10 to about 264. Morepreferably, the aluminosilicate has the formula

Na₁₂[(AIO₂)₁₂.(SiO₂)₁₂]xH₂O

wherein x is from about 20 to about 30, preferably about 27. Thesepreferred aluminosilicates are available commercially, for example underdesignations Zeolite A, Zeolite B and Zeolite X. Alternatively,naturally-occurring or synthetically derived aluminosilicate ionexchange materials suitable for use herein can be made as described inKrummel et al, U.S. Pat. No. 3,985,669, the disclosure of which isincorporated herein by reference.

The aluminosilicates used herein are further characterized by their ionexchange capacity which is at least about 200 mg equivalent of CaCO₃hardness/gram, calculated on an anhydrous basis, and which is preferablyin a range from about 300 to 352 mg equivalent of CaCO₃ hardness/grain.Additionally, the instant aluminosilicate ion exchange materials arestill further characterized by their calcium ion exchange rate which isat least about 2 grains Ca⁺⁺/gallon/minute/-gram/gallon, and morepreferably in a range from about 2 grainsCa⁺⁺/gallon/minute/-gram/gallon to about 6 grainsCa⁺⁺/gallon/minute/-gram/gallon .

The non-particulate detergent product

The detergent tablets can be prepared simply by mixing the solidingredients together and compressing the mixture in a conventionaltablet press as used, for example, in the pharmaceutical industry.

The detergent tablets provided can be made in any size or shape. Priorto compaction, the detergent particles may be surface treated with aflow aid according to the present invention. The detergent tabletsprovided may be manufactured by using any compacting process, such astabletting, briquetting, or extrusion, preferably tabletting. Suitableequipment includes a standard single stroke or a rotary press (such asCourtoy®, Korch®, Manesty®, or Bonals®). As used herein, the term“non-particulate detergent product” includes physical shapes such astablets, blocks, bars and the like.

Coating for non-particulate detergent product

In one embodiment, the tablets are coated with a coating in order toprovide mechanical strength and shock and chip resistance to thecompressed tablet core. The tablets are coated with a coating that issubstantially insoluble in water so that the tablet does not absorbmoisture, or absorbs moisture at only a very slow rate. The coating isstrong so that moderate mechanical shocks to which the tablets aresubjected during handling, packing and shipping result in no more thanvery low levels of breakage or attrition. Further, the coating ispreferably brittle so that the tablet breaks up when subjected tostronger mechanical shock. Furthermore it is advantageous if the coatingmaterial is dissolved under alkaline conditions, or is readilyemulsified by surfactants. This avoids the deposition of undissolvedparticles or lumps of coating material on the laundry load. This may beimportant when the coating material is completely insoluble (for exampleless than 1 g/l) in water.

As defined herein “substantially insoluble” means having a very lowsolubility in water. This should be understood to mean having asolubility in water at 25° C. of less than 20 g/L, preferably less than5 g/l, and more preferably less than 1 g/l. Water solubility is measuredfollowing the test protocol of ASTM E1148-87 entitled, “Standard TestMethod for Measurements of Aqueous Solubility”.

Suitable coating materials are fatty acids, adipic acid and C8-C13dicarboxylic acids, fatty alcohols, diols, esters and ethers. Preferredfatty acids are those having a carbon chain length of from C12 to C22and most preferably from C18 to C22. Preferred dicarboxylic acids areadipic acid (C6), suberic acid (C8), azelaic acid (C9), sebacic acid(C10), undecanedioic acid (C11), dodecanedioic acid (C12) andtridecanedioic acid (C13). Preferred fatty alcohols are those having acarbon chain length of from C12 to C22 and most preferably from C14 toC18. Preferred diols are 1,2-octadecanediol and 1,2-hexadecanediol.Preferred esters are tristearin, tripalmitin, methylbehenate,ethylstearate. Preferred ethers are diethyleneglycol monohexadecylether, diethyleneglycol mono octadecylether, diethyleneglycolmono tetradecylether, phenylether, ethyl naphtyl ether, 2methoxynaphtalene, beta naphtyl methyl ether and glycerolmonooctadecylether. Other preferred coating materials include dimethyl2,2 propanol, 2 hexadecanol, 2 octadecanone, 2 hexadecanone, 2, 15hexadecanedione and 2 hydroxybenzyl alcohol. The coating is ahydrophobic material having a melting point preferably of from 40° C. to180° C.

In the preferred embodiment, the coating can be applied in a number ofways. Two preferred coating methods are a) coating with a moltenmaterial and b) coating with a solution of the material. In a), thecoating material is applied at a temperature above its melting point,and solidifies on the tablet. In b), the coating is applied as asolution, the solvent being dried to leave a coherent coating. Thesubstantially insoluble material can be applied to the tablet by, forexample, spraying or dipping. Normally when the molten material issprayed on to the tablet, it will rapidly solidify to form a coherentcoating. When tablets are dipped into the molten material and thenremoved, the rapid cooling again causes rapid solidification of thecoating material. Clearly substantially insoluble materials having amelting point below 40° C. are not sufficiently solid at ambienttemperatures and it has been found that materials having a melting pointabove about 180° C. are not practicable to use. Preferably, thematerials melt in the range from 60° C. to 160° C., more preferably from70° C. to 120° C.

By “melting point” is meant the temperature at which the material whenheated slowly in, for example, a capillary tube becomes a clear liquid.For most purposes, the coating forms from 1% to 10%, preferably from1.5% to 5%, of the tablet weight.

Addition of flow aids

In one embodiment, the process includes adding a flow aid to theparticulate detergent composition in a range of from about 0. 1% toabout 25% by weight of the particulate detergent composition beforecompaction.

As used herein, the term “flow aids” means any material capable of beingdeposited on to the surface of detergent particles so as to reduce thestickiness of the detergent particles and allow them to flow freely.Flow aids could include porous carrier particles selected from the groupconsisting of amorphous silicates, crystalline nonlayer silicates, layersilicates, calcium carbonates, calcium/sodium carbonate double salts,sodium carbonates, clays, zeolites, sodalites, alkali metal phosphates,macroporous zeolites, chitin microbeads, carboxyalkylcelluloses,carboxyalkylstarches, cyclodextrins, porous starches and mixturesthereof.

The preferred flow aids are zeolite A, zeolite X, zeolite Y, zeolite P,zeolite MAP and mixtures thereof. The term “zeolite” used herein refersto a crystalline aluminosilicate material. The structural formula of azeolite is based on the crystal unit cell, the smallest unit ofstructure represented by

Mm/n[(AIO2)m(SiO2)y].xH2O

where n is the valence of the cation M, x is the number of watermolecules per unit cell, m and y are the total number of tetrahedra perunit cell, and y/m is 1 to 100. Most preferably, y/m is 1 to 5. Thecation M can be Group IA and Group IIA elements, such as sodium,potassium, magnesium, and calcium.

In the preferred embodiment of the present invention, the flow aid isadded in an amount in a range, desirably, from about 0.1% to about 25%by weight of the particulate detergent, more desirably from about 1% toabout 15% by weight, preferably from about 1% to about 10% by weight,and most preferably in an amount of about 5% by weight. It isundesirable to add more than 25% by weight of the flow aid because tooexcessive a force would be needed to make the detergent particles tostick together and stay in a particulate form. Flow aid addition in anamount less than about 0.1% by weight is also undesirable because littleor no reduction in the stickiness of the detergent particles wouldoccur, which upon compression into a particulate form would cause theresultant detergent tablet to not disintegrate readily when placed inwater in a washing machine.

In one embodiment, the flow aids have a perfume adsorbed on theirsurface before being deposited on the detergent particles. Preferably,the flow aids are zeolites preferably containing less than about 20%desorbable water, more preferably less than about 8% desorbable water,and most preferably less than about 5% desorbable water. Such materialsmay be obtained by first activating/dehydrating by heating to about 150to 350° C., optionally with reduced pressure (from about 0.001 to about20 Torr). After activation, the perfume is slowly and thoroughly mixedwith the activated zeolite and, optionally, heated to about 60° C. forup to about 2 hours to accelerate absorption equilibrium within thezeolite particles. The perfume/zeolite mixture is then cooled to roomtemperature and is in the form of a free-flowing powder. The term“perfume” is used to indicate any odoriferous material which issubsequently released into the aqueous bath and/or onto fabricscontacted therewith. The perfume will most often be liquid at ambienttemperatures. A wide variety of chemicals are known for perfume uses,including materials such as aldehydes, ketones and esters. Morecommonly, naturally occurring plant and animal oils and exudatescomprising complex mixtures of various chemical components are known foruse as perfumes. The perfumes herein can be relatively simple in theircompositions or can comprise highly sophisticated complex mixtures ofnatural and synthetic chemical components, all chosen to provide anydesired odor. Typical perfumes can comprise, for example, woody/earthybases containing exotic materials such as sandalwood, civet andpatchouli oil. The perfumes can be of a light floral fragrance, e.g.,rose extract, violet extract, and lilac. The perfumes can also beformulated to provide desirable fruity odors, e.g., lime, lemon, andorange. Any chemically compatible material which exudes a pleasant orotherwise desirable odor can be used in the perfumed compositionsherein. Perfumes also include pro-fragrances such as acetalpro-fragrances, ketal pro-fragrances, ester pro-fragrances (e.g.,digeranyl succinate), hydrolyzable inorganic-organic pro-fragrances, andmixtures thereof. These pro-fragrances may release the perfume materialas a result of simple hydrolysis, or may be pH-change-triggeredpro-fragrances (e.g., pH drop) or may be enzymatically releasablepro-fragrances.

In the preferred embodiment, the amount of perfume adsorbed on thecarrier material, such as zeolite for example, is preferably in therange of about 0.1% to about 50% by weight, more preferably in the rangeof about 0.5% to about 25% by weight, and most preferably in the rangeof about 1% to about 15% by weight of zeolite powder.

Compaction of particulate detergent to form non-particulate detergentproduct

In the preferred embodiment, the process still further includes the stepof compacting the particulate detergent composition having the bleachactivators by applying a pressure in an amount sufficient to form thenon-particulate detergent product having a density of at least about1000 g/l. It is desirable to form a detergent tablet that has a densityof at least about 1000 g/l so that the tablet will sink in water. If thedensity of the detergent tablet is less than about 1000 g/l, the tabletwill float when placed in the water in a washing machine and this willdetrimentally reduce the dissolution rate of the tablet in the water. Itis desirable to apply at least that much pressure as is sufficient tocompress the particulate detergent material to form a tablet having adensity of at least about 1000 g/l. Too little a pressure will result ina compressed tablet with a density less than about 1000 g/l.

EXAMPLE A

Detergent tablets are formed from detergent particles having bleachactivator particles (NOBS) having a particle size in the range of 200microns to 2000 microns, according to the following composition:

TABLE A.1 Particulate detergent Ingredients % by weight C₁₂₋₁₆ linearalkylbenzene sulfonate 8.80 C₁₄₋₁₅ alkyl sulfate/C₁₄₋₁₅ alkyl ethoxysulfate 8.31 C₁₂₋₁₃ alkyl ethoxylate 1.76 polyacrylate (MW = 4500) 2.40polyethylene glycol (MW = 4000) 0.96 sodium sulfate 8.40 aluminosilicate21.28 sodium carbonate 16.80 protease enzyme 0.32 sodium perboratemonohydrate 2.08 lipase enzyme 0.17 cellulase enzyme 0.08 NOBS extrudate4.80 citric acid monohydrate 2.25 sodium bicarbonate 2.75 sodium acetate15.00 free water 1.60 other minor ingredients (perfume etc.) 2.24 Total100.00

The detergent tablet formed is coated with a coating according to thefollowing composition:

TABLE A.2 Ingredient % by weight Detergent 91.10 Coating: dodecanediocacid 8.00 carboxymethyl cellulose 0.90 Total 100.00

Optionally, a flow aid (zeolite) is also added to the particulatedetergent composition in about 5% by weight of the detergent and mixedby one of various methods, such as agitation for example.

The tablets are formed by compressing the tablet ingredients in acylindrical die having a diameter of 55 mm using a laboratory presshaving a trade name Carver Model 3912, to form a tablet having a heightof 20 mm. The formed tablets were then coated with the protectivecoating by dipping the tablet into a molten bath of the coating forabout 3 seconds. The molten coating bath is maintained at a temperatureof about 145 degrees centigrade.

The term “NOBS extrudate” as used herein, is an acronym for the chemicalsodium nonanoyloxybenzene sulfonate, commercially available from EastmanChemicals, Inc. The carboxymethyl cellulose used in the above example iscommercially available from Metsa-Serla and sold under the trade name,Nymcel ZSB-16.

In another embodiment of the present invention, a method of launderingfabric materials in a washing machine includes the steps of providing aflexible porous bag adapted for receiving a non-particulate detergentproduct, providing a non-particulate detergent product having a bleachactivator with particle size in a range of from about 100 microns toabout 4000 microns, in a weight range of from about 0.1% to about 15% byweight, the non-particulate detergent having a density of at least 1000g/l, according to the present invention as described herein, placing thenon-particulate detergent product within the flexible porous bag, andplacing the flexible porous bag containing the detergent product in thewashing machine with the fabric materials to be washed.

The flexible porous bag is permeable to water and to the washing mediumand is thus adapted for permitting entry of an aqueous washing mediumthrough the bag, thereby dissolving the non-particulate detergentproduct placed therein, into the aqueous washing medium, and releasing aresultant wash solution from inside of the bag to outside of the bag andinto the aqueous wash medium during a wash cycle.

The flexible porous bag is made of a material capable of retaining thenon-particulate detergent product without allowing it to pass throughuntil the detergent product has dissolved in the washing medium. The bagis also made of a material capable of withstanding the temperatures ofwashing laundry in a washing machine. The process of the invention maybe applied not only to non-particulate detergents but also to anynon-particulate product which is active during washing, such as, forexample, bleaching agents, such as agents releasing chlorine or activeoxygen (peroxygen compounds), bleaching catalysts, bleaching activators,bactericides, foam regulators, whiteners, agents preventing there-deposition of soil, enzymes, softeners, agents capable of removinggrease stains or other constituents having no direct effect on thesoiling but capable of taking part in the laundry washing process.

The flexible bag may be made from any material which offers a sufficientresistance to water, such as a woven or non-woven material produced fromnatural or synthetic fibers. For example, the bag is formed of purecotton either in the form of a fabric with a mesh opening of less thanabout 0.5 mm or in the form of a non-woven article with openings havinga size in a range of from about 0.5 mm to about 0.8 mm.

Accordingly, having thus described the invention in detail, it will beobvious to those skilled in the art that various changes may be madewithout departing from the scope of the invention and the invention isnot to be considered limited to what is described in the specification.

What is claimed is:
 1. A laundry detergent tablet comprising: a bleachactivator having the general formula

wherein R is an alkyl group containing from 5 to 18 carbon atoms whereinthe longest linear alkyl chain extending from and including the carbonylcarbon contains from 6 to 10 carbon atoms and L is a leaving group, theconjugate acid of which has a pK_(α) in the range of from 6 to 13; saidbleach activator being in particulate form and having a particle size ina range of from 100 microns to 4000 microns; said bleach activator beingpresent in a range of from 0.1% to 15% by weight of said non-particulatedetergent product; from about 0.1% to about 75% by weight of a peroxygenbleaching compound, wherein said bleach activator is dispersed within amatrix of said detergent tablet, said matrix having a density of atleast 1000 g/l, further wherein said tablet is coated with awater-insoluble material selected from the group consisting of C12-C22fatty acids, adipic acid, C8-C13 dicarboxylic acids and mixturesthereof.
 2. The tablet of claim 1 wherein said particle size is in therange of from 200 microns to 3000 microns.
 3. The tablet of claim 2wherein said particle size is in the range of from about 200 microns toabout 2000 microns.
 4. The tablet of claim 1 wherein said particle sizeis in the range of from about 200 microns to about 1500 microns.
 5. Thetablet of claim 1 wherein said particle size is in the range of fromabout 300 microns to about 1000 microns.
 6. The tablet of claim 1wherein said bleach activator is present in a range of from about 1% toabout 10% by weight of said tablet.
 7. The tablet of claim 6 whereinsaid bleach activator is present in a range of from about 1% to about 8%by weight of said tablet.
 8. The tablet of claim 1 wherein saidperoxygen bleaching compound selected from the group consisting ofsodium perborate monohydrate, sodium perborate tetrahydrate, sodiumcarbonate peroxyhydrate, sodium pyrophosphate peroxyhydrate, ureaperoxyhydrate, sodium peroxide and mixtures thereof.
 9. The tablet ofclaim 1 wherein R is a linear alkyl chain containing from about 5 toabout 12 and L is selected from the group consisting of:

wherein R² is a linear alkyl chain containing from about 2 to about 6carbon atoms, R³ is an alkyl chain containing from about 1 to about 8carbon atoms, and Y is —SO₃ ⁻M⁺ or —CO₂ ⁻M⁺ wherein M is an alkalimetal, ammonium or substituted ammonium cation.
 10. The tablet of claim1 wherein R is a linear alkyl chain containing from about 5 to about 12carbon atoms and L is selected from the group consisting of:

wherein R² is a linear alkyl chain containing from about 2 to about 6carbon atoms, Y is —SO₃M+ or —COO—M+ wherein M is hydrogen, an alkalimetal, ammonium or substituted ammonium cation.
 11. The tablet of claim1 wherein said bleach activator has the formula:

wherein R is a linear alkyl chain containing from about 5 to about 9 andM is sodium or potassium.
 12. The tablet of claim 1 wherein said bleachactivator is sodium nonanoyloxybenzene sulfonate.
 13. The tablet ofclaim 1 wherein said bleach activator is sodiumbenzoyloxybenzenesulfonate.
 14. The tablet of claim 1 wherein saidbleach activator in particulate form is coated with from about 0.1% toabout 10% by weight of a flow aid selected from the group consisting offinely divided aluminosilicates, silicas, crystalline layered silicatesMAP zeolites, citrates, amorphous silicates, sodium carbonates andmixtures thereof.
 15. The tablet of claim 14 further comprising adjunctdetergent ingredients selected from the group consisting of enzymes,soil release agents, dispersing agents, optical brighteners, sudssuppressors, fabric softeners, enzyme stabilizers, perfumes, dyes,fillers, dye transfer inhibitors, and mixtures thereof.
 16. A method oflaundering soiled clothes comprising the step of immersing said soiledclothes in an aqueous medium containing an effective amount of a tabletaccording to claim
 1. 17. A method of laundering fabric materials in awashing machine, comprising the steps of: providing a flexible porousbag adapted for receiving a detergent tablet; providing a detergenttablet according to claim 1; placing said detergent tablet within saidflexible porous bag; placing said flexible porous bag containing saidtablet in said washing machine with said fabric materials to be washed;and said flexible porous bag being adapted for permitting entry of anaqueous washing medium through said bag, thereby dissolving saiddetergent tablet placed therein, into said aqueous washing medium, andreleasing a resultant wash solution from inside of said bag to outsideof said bag into said aqueous wash medium during a wash cycle.